Vascular Stroke and antithrombotics. Top left, the brain in frontal section with its vascularization. A zoom of a vessel in section leaves the brain to detail the cascade of coagulation in the formation of a clot or thrombus (lower right). In the liver (top right) Inactive vitamin K (yellow beads) become active (yellow stars) with epoxide reductase. Active vitamin K will activate the coagulation factors that will, in turn, lead to the coagulation cascade in the blood vessel. In yellow on the left wall of the vessel an atheromatous plaque will release the tissue factor (VII). Below, to the left of the clot, a wafer (white) in aggregation phase.